CPU: The future of GPU?

For those who play PC games (and please count me in), the most expensive and necessary investment has always been the graphics card (also known as the GPU, graphics processing unit). High-end cards, from either ATI or nVidia, can cost $500 and up. That's not even factoring in the case, cooling system, power supply, etc., which also have to be equally high-end to support the increasingly large and power-hungry graphics cards. And there seems to be no end to all this. Or is there?

At IDF 2007, there was a demo running Quake 4. There wasn't much to talk about the demonstration itself (the game has been out for a while). As a matter of fact, there was no real game action on the screen--just a character walking around in a smooth 3D environment with excellent-looking lighting and shadow effects. What was impressive was the fact that the computer didn't have a graphics card in it, such as the Nvidia GeForce 8800 GTX, as one would have expected. Instead, the graphics were powered by an Intel multicore CPU that incorporates ray tracing display technology.

Unlike conventional GPUs that use raster graphics techniques to display graphics content, ray tracing models the behavior of light to create shadows and reflections for a more photorealistic presentation of 3D and 2D content. The concept of ray tracing is not new and rather simple: simulating the path that light rays take as they bounce around within the environment, while determining the color of each light ray that strikes the display before reaching the eyes. However, the sheer number of light rays needed to be traced requires a huge amount of computation. That is why this concept had to wait until now to come closer to reality (and indeed very close, judging by the demo), with multicore CPUs. It's predicted that in about three years, there will be computers that use processor-based ray tracing display technology. This means a gaming computer can have less components, be more energy efficient, quieter, and probably cheaper too.

As the ray tracing technique is completely different from the current raster technique, current games will not work with this technique and will need to be re-engineered (or ported) in order to take advantage of the new display platform. This is similar to how an Xbox 360 game will not run on a PS3 and vice versa. However, change takes time, and this is to be expected. And it's not like I am in a rush to discard my recent hefty investment in my SLI system. I will, though, try not to think about how many light rays there are that come out of my screen while flying over Outland.